Now, if I am right in thinking that art is a manifestation--a manifestation, mark, and not an expression--of man's spiritual state, then in the history of art we shall read the spiritual history of the race. I am not surprised that those who have devoted their lives to the study of history should take it ill when one who professes only to understand the nature of art hints that by understanding his own business he may become a judge of theirs. Let me be as conciliatory as possible. No one can have less right than I, or, indeed, less inclination to assume the proud title of "scientific historian": no one can care less about historical small-talk or be more at a loss to understand what precisely is meant by "historical science." Yet if history be anything more than a chronological catalogue of facts, if it be concerned with the movements of mind and spirit, then I submit that to read history aright we must know, not only the works of art that each age produced, but also their value as works of art. If the aesthetic significance or insignificance of works of art does, indeed, bear witness to a spiritual state, then he who can appreciate that significance should be in a position to form some opinion concerning the spiritual state of the men who produced those works and of those who appreciated them. If art be at all the sort of thing it is commonly supposed to be, the history of art must be an index to the spiritual history of the race. Only, the historian who wishes to use art as an index must possess not merely the nice observation of the scholar and the archaeologist, but also a fine sensibility. For it is the aesthetic significance of a work that gives a clue to the state of mind that produced it; so the ability to assign a particular work to a particular period avails nothing unaccompanied by the power of appreciating its aesthetic significance.